1. Field of the Invention
The present invention relates to a method and system for managing virtual memory, and particularly for flash memory.
2. Description of the Related Art
Non-volatile semiconductor memory, such as flash memory, is useful for relatively long-term storage in computer systems, more particularly, for pocket PC. Spare regions of flash memories have an advantage of storing various extensions of software, for example, CPQ OPTION JACKET, important documents or data, and others.
It is not easy to access flash memory. Flash memories, like a hard disk, are divided into pages and blocks. Rather than writing to just one word in a page, the entire page must be written to at the same time, and individual bytes cannot be written. The page must be cleared of any previous data before being written, clearing is accomplished by a flash erase cycle. An entire block pages is erased at once. For example, if a block has 16 pages, the entire block of 16 pages must be erased at once, while all 512 bytes on a page must also be written together.
To make flash memory easy for users to store code and data, there is a need for a virtual memory management system and method to realize a flash-file system.